Synthesis and Surface Modifications of Au Nanostars and Their Applications in Biomedical Fields

Au nanostars (AuNSs) with the complex three. dimensional structure have become a new type of nanomaterials with a rapid development of nanotechnology. AuNSs have unique physical and chemical properties such as tunable optical properties of localized surface plasmon resonance (LSPR), surface. enhanced Raman scattering (SERS) effect, photothermal properties, and the large surface-to-volume ratio. For this reason, there's great potential for their applications in the fields of nanomaterials and biomedicine. In this article, we firstly evaluate the optical properties of AuNSs and explain their theoretical basis. Then two main methods of preparing AuNSs in recent years are summarized, including seed-mediated synthesis method and one-step method. At the same time, a discussion of the merits and drawbacks of each method is also made. In terms of functionalized probes' assembly, two principal ways of surface modifications are introduced, including silica-coated AuNSs and modification of AuNSs using polymer or biomolecules. In the way of application, the recent progress of AuNSs applied in biomolecular detection, medical imaging, diagnosis and photothermal therapy of tumors, delivery and controlled release of drug is reviewed. In the end, we discuss some problems in the preparation and application of AuNSs. What's more, the future research content and research direction in this field are prospected.